Code division multiple access unit and code division multiple access method

Abstract

The present invention comprises addition/subtraction means 101 to 107 and exclusive OR circuits 111 to 125. The addition/subtraction means performs addition (A+B: sub/add=0) or subtraction (A-B: sub/add=1) according to a logic value of the control terminal sub/add. The transmission amplitude signals amp0 to amp7 with a plural bits width are input to the addition/subtraction means 101 to 104 at each two channels. The exclusive OR 10 circuits 111 to 118 calculates an exclusive OR of the transmission data d0 to d7 and the spread code sequence signals c0 to c7. The resultant code sequence signals s0 to s7 are input to the control terminals sub/add's of the addition/subtraction means. The addition/subtraction means 108 at the last step inverts the code and outputs the spread synthesis signal sum spread with spread code sequence signal c0 to c7.

What is claimed is: 
     
       1. A code division multiple access unit for spreading and synthesizing transmission signals of a plurality of channels by using a spread spectrum system comprising: first logic processing means for producing a transmission code sequence based on a logic of a transmission signal and a spread code sequence at each channel;   addition/subtraction means for adding and/or subtracting a transmission amplification signal of said each channel; and   second logic processing means for producing a control signal which controls addition and/or subtraction of said addition/subtraction means based on said transmission code sequence produced by said first logic processing means.   
     
     
       2. A code division multiple access unit for spreading and synthesizing transmission signals of a plurality of channels by using a spread spectrum system comprising: first logic processing means for producing a transmission code sequence based on a logic of a transmission signal and a spread code sequence at each channel, said first logic processing means comprising a plurality of exclusive OR circuits for producing a transmission code sequence by obtaining an exclusive OR of a transmission signal and a spread code sequence at each channel;   addition/subtraction means for adding and/or subtracting a transmission amplification signal of said each channel; and   second logic processing means for producing a control signal which controls addition and/or subtraction of said addition/subtraction means based on said transmission code sequence produced by said first logic processing means.   
     
     
       3. A code division multiple access unit for spreading and synthesizing transmission signals of a plurality of channels by using a spread spectrum system comprising: first logic processing means for producing a transmission code sequence based on a logic of a transmission signal and a spread code sequence at each channel;   addition/subtraction means for adding and/or subtracting a transmission amplification signal of said each channel; and   second logic processing means for producing a control signal which controls addition and/or subtraction of said addition/subtraction means based on said transmission code sequence produced by said first logic processing means, said second logic processing means comprising a plurality of exclusive OR circuits for producing a control signal which controls said addition/subtraction means by obtaining an exclusive OR of two values of transmission code sequence.   
     
     
       4. A code division multiple access unit for spreading and synthesizing transmission signals of a plurality of channels by using a spread spectrum system comprising: first logic processing means for producing a transmission code sequence based on a logic of a transmission signal and a spread code sequence at each channel, said first logic processing means producing a code sequence representing polarity of a transmission signal of each channel by obtaining an exclusive OR of a transmission signal and a spread code sequence for predetermined channel at each channel;   addition/subtraction means for adding and/or subtracting a transmission amplification signal of said each channel, said addition/subtraction means producing a first input terminal and a second input terminal, wherein a transmission amplification signal input to said first input terminal and a transmission amplification signal input to said second input terminal are added to be synthesized when said control signal indicates addition and a transmission amplification signal input to said second input terminal is subtracted from a transmission amplification signal input to said first input terminal to be synthesized when said control signal indicates subtraction;   second logic processing means for producing a control signal which controls addition and/or subtraction of said addition/subtraction means based on said transmission code sequence produced by said first logic processing means, said second logic processing means producing said control signal by obtaining an exclusive OR of a transmission code sequence corresponding to a channel of transmission amplification signal input to said first input terminal of said addition/subtraction means in a previous stage among channels corresponding to transmission amplification signals input to said first input terminal of said addition/subtraction means; and   a transmission code sequence correspond to a channel of the transmission amplification signal input to said first input terminal of said addition/subtraction means in a previous stage among channels corresponding to transmission amplification signals input to said second input terminal of said addition/subtraction means.   
     
     
       5. A code division multiple access unit for spreading and synthesizing transmission signals of a plurality of channels by using a spread spectrum system comprising: first logic processing means for producing a transmission code sequence based on a logic of a transmission signal and a spread code sequence at each channel;   addition/subtraction means for adding and/or subtracting a transmission amplification signal of said each channel;   second logic processing means for producing a control signal which controls addition and/or subtraction of said addition/subtraction means based on said transmission code sequence produced by said first logic processing means; and   a second addition/subtraction means provided with a first input terminal receiving an input of a low level signal and a second input terminal receiving an input of a transmission amplification signal obtained by synthesizing transmission amplification signals of a plurality of channels for inverting said synthesized transmission amplification signal based on a transmission code sequence of a predetermined channel.   
     
     
       6. A code division multiple access unit for spreading and synthesizing transmission signals of a plurality of channels by using a spread spectrum system comprising: a plurality of first exclusive OR circuits, each of said first exclusive OR circuits for producing a transmission code sequence of said predetermined channel by obtaining an exclusive OR of a transmission signal of a predetermined channel and a spread code sequence of said predetermined channel;   a plurality of first addition/subtraction means, each of said first addition/subtraction means provided with a first input terminal and a second input terminal for adding a transmission amplification signal input to said first input terminal and a transmission amplification signal input to said second input terminal for performing synthesis when a first control signal indicates addition and for subtracting a transmission amplification signal input to said second input terminal from a transmission signal input to said first input terminal for performing synthesis when a second control signal indicates subtraction;   a plurality of second exclusive OR circuits, each of said second exclusive OR circuits for producing said first control signal by obtaining an exclusive OR of a transmission code sequence of a channel corresponding to a transmission amplification signal input to said first input terminal of said first addition/subtraction means and a transmission code sequence of a channel corresponding to a transmission amplification signal input to said second input terminal of said first addition/subtraction means;   a plurality of second addition/subtraction means provided with a first input terminal and a second input terminal to which a transmission amplification signals obtained by synthesizing signals of plural channels are input for adding a transmission amplification signal input to said first input terminal and a transmission amplification signal input to said second input terminal for performing synthesis when said second control signal indicates addition, and subtracting a transmission amplification signal input to second input terminal from a transmission amplification signal input to said first input terminal for performing synthesis when said second control signal indicates subtraction;   a plurality of third exclusive OR circuits for producing said second control signal by obtaining an exclusive OR of a transmission code sequence corresponding to a channel of a transmission amplification signal input to said first terminal of said addition/subtraction means in a previous stage among channels corresponding to transmission amplification signals input to said first input terminal of said second addition/subtraction means and a transmission code sequence corresponding to a channel of transmission amplification signal input to said first input terminal of said addition/subtraction means in a previous stage among channels corresponding to transmission amplification signal input to said second input terminal of said second addition/subtraction means; and   a third addition/subtraction means provided with a first input terminal to which a low level signal is input and a second input terminal to which a transmission amplification signal obtained by synthesizing transmission amplification signals of plural channels is input for inverting said synthesized transmission amplification signal based on a transmission code sequence of a predetermined channel.   
     
     
       7. The code division multiple access unit of claim 6 with n channels (n is an even number), comprising n units of said first exclusive OR circuit, n/2 units of said second exclusive OR circuit, (n/2-1) units of said third exclusive OR circuit, n/2 units of said first addition/subtraction means and (n/2-1) units of said second addition/subtraction means. 
     
     
       8. The code division multiple access unit of claim 6 with n channels (n is an odd number), comprising n units of said first exclusive OR circuit, (n-1)/2 units of said second exclusive OR circuit, (n-1)/2 units of said third exclusive OR circuit, (n-1)/2 units of said first addition/subtraction means and (n-1)/2 units of said second addition/subtraction means. 
     
     
       9. A code division multiple access method for spreading and synthesizing transmission signals of a plurality of channels by using a spread spectrum system, said method comprising steps of: producing a polar code sequence representing polarity of a transmission amplification signal of said predetermined channel based on a logic of a transmission signal of a predetermined channel and spread code sequence of said predetermined channel at every channel;   producing a control signal based on a logic of a polar code sequence at each pair of two values of said polar code sequence; and   synthesizing transmission amplification signal equivalent to 1 pair by adding and/or subtracting based on a control signal of each pair.   
     
     
       10. The code division multiple access method of claim 9, wherein said step of producing said polar code sequence comprises a step of producing a polar code sequence representing polarity of a transmission signal of said predetermined channel by obtaining an exclusive OR of a transmission signal of a predetermined channel and spread code sequence of said predetermined channel. 
     
     
       11. The code division multiple access method of claim 9, wherein said step of producing said control signal comprises a step of producing said control signal by obtaining an exclusive OR of said polar code sequence at each pair formed of two values of said polar code sequence. 
     
     
       12. The code division multiple access method of claim 9 further comprising a step of inverting a transmission amplification signal obtained by synthesizing through adding or subtracting said synthesized transmission amplification signal and a low level signal based on a predetermined polar code sequence.